This invention relates to an improved grounding tank type arrester.
In a conventionally known grounding tank type arrester such as disclosed in, for example, JP-A-55-115279, with the view of reducing the height of the arrester, a plurality of columns each including a stack in which an element made of zinc oxide and an insulating spacer are stacked alternately are arranged on a circle, the heights of individual zinc oxide elements of one column are made to slightly differ from the heights of individual zinc oxide elements of another column, and the zinc oxide elements 71 to 74 of one column and adjoining columns are sequentially interconnected together toroidally by means of bridge conductor plates 75 to 78, as illustrated in FIGS. 9A and 9B.
However, in the prior art grounding tank type arrester, because of the toroidal connection throughout the zinc oxide elements, the residual inductance of the arrester as a whole increases, raising a problem that a current passed through the arrester under the application of an impulse voltage due to thunderbolt causes a voltage across the residual inductance and the limit voltage tends to increase depending on a waveform of the developing voltage.
An arrester suggesting a way to reduce the residual inductance has been proposed as disclosed in, for example, JP-A-54-54258, according to which a plurality of zinc oxide elements are connected in series to form one block, a plurality of such blocks are connected in series to form one section and a plurality of such sections are connected in series in such a manner that the direction of current flowing through one section is inverse to the direction of current flowing through the adjoining section.
Further, for example, JP-A-53-91360 discloses an arrester wherein a plurality of columns respectively include a plurality of zinc oxide elements and zinc oxide elements included in the respective columns and being flush with each other are mutually interconnected by conductor plates.
The arresters of the above prior art references are disadvantageous in that the zinc oxide element as a constituent of each of the plural columns and the insulating spacer for insulating the zinc oxide element have different thicknesses and the number of columns constituting the arrester is limited, bottlenecking simplified and rapid production of the arrester. This invention intends to solve the above problems.